Archelon is a genus of extinct sea turtles whose fossils have been found in North America, particularly South Dakota and Colorado. The word archelon itself has no synonyms, but the genus belongs to the family Cheloniidae, which includes modern sea turtle species such as the green sea turtle, loggerhead sea turtle, and hawksbill sea turtle. While the physical characteristics of archelon may differ from those of modern sea turtles, they are all members of the same taxonomic family. Other synonyms for archelon may include "giant turtle" or "prehistoric turtle", as these descriptors could be used for any large, extinct turtle species.